A. Field of the Invention
The present invention relates to the field of internal combustion engines, more specifically, the rocker arm pivot point.
Internal combustion engines are constantly evolving. Internal combustion engines are always being modified to improve performance or to improve efficiency. This is more important with the ever-increasing cost of gasoline and diesel fuels. One component of a gasoline engine that is in want of increased variability is the rocker arm of the valve timing of the internal combustion engine. There have been many attempts over the years to provide for variability in the timing of the internal combustion engine and/or to variably adjust the lift of the valve stem.
The device of the present application seeks to address this need by providing a purely mechanical means with which to adjust the timing as well as the lift of the rocker arm.
B. Discussion of the Prior Art
As a preliminary note, it should be stated that there is an ample amount of prior art that deals with variable lift and timing systems, generally speaking. However, no prior art discloses a mechanically operated variable timing device that works to adjust the location of a pivot point, for a rocker arm such that the pivot point may be adjusted along a vertical axis, and which is adjusted independent of RPM of the respective engine, and which is able to adjust the valve timing and lift to optimize timing and lift at different RPMs; wherein the mechanically operated variable timing device includes a cam that is able to rotate independent of engine RPM, and which engages a plunger positioned over the respective rocker arm; wherein the plunger is biased upwardly via a spring positioned between the ball fulcrum of the rocker arm and a bottom portion of the plunger; wherein a pivot shaft is threadably engaged to a threaded hole located on a top surface of the engine block; wherein the pivot shaft extends vertically through the rocker arm and ball fulcrum; wherein the pivot shaft extends into a bottom cavity located in the plunger in order to support the various componentry associated with the mechanically operated variable timing device.
The Bonvallet Patent (U.S. Pat. No. 4,724,822) discloses a variable valve lift and timing valve train mechanism that includes a rocker arm, valve actuator, and reaction member. However, the mechanism employs the use of a hydraulic lash adjuster in conjunction with the reaction member and a spring to adjust the pivot point of the rocker arm. Moreover, the mechanism is a purely mechanically operated device that is linearly aligned along a vertical axis in order to raise and lower the pivot point.
The Zubeck Patent (U.S. Pat. No. 6,491,008) discloses a variable valve timing adjustable roller rocker arm assembly that includes an adjustment cam operates to move a cam roller along the rocker arm. Though the linkage and cam roller are purely mechanical in operation, they do not use a configuration that adjust the pivot point along a vertical axis via a limiter, secondary spring, and ball fulcrum that push downwardly to limit the location of the pivot point of the rocker arm.
The Skelley Patent (U.S. Pat. No. 4,502,426) discloses a variable valve lift and timing mechanism that uses a hydraulic cylinder moving an actuating piston that is mechanically linked to the pivot shaft for controlling the same. Again, not a purely mechanical system that adjusts the pivot point along a vertical axis via an adjustable limiter stop, secondary spring, and ball fulcrum.
The Magnan et al. Patent (U.S. Pat. No. 7,913,656) discloses a variable displacement engine having selectively engageable rocker arm with positioning device. Again the selectively engageable rocker arm with positioning device is not a limiting cam that rotates to adjust the pivot point of the rocker arm along a vertical axis, and independent of engine RPM.
The Wride Patent (U.S. Pat. No. 4,901,684) discloses a variable lift cam follower that can vary the timing and lift of a valve upon rotation of the support. Again, the mechanism is not a purely mechanical device that adjusts the timing and lift via changing the pivot point of the rocker arm along a vertical axis.
The Furnivall Patent (U.S. Pat. No. 5,107,803) discloses a split-action rocker arm that is mountable on an engine rocker shaft for transmitting the rotational motion of a cam on a camshaft into the linear motion of a valve lifter. Again, the split-action rocker arm is not a purely mechanical system that adjusts the pivot point of a rocker arm along a vertical axis in order to adjust lift and timing of the respective valve(s).
The Hara et al. Patent (U.S. Pat. No. 4,526,142) discloses a variable valve timing arrangement for an internal combustion engine or the like. Again, the arrangement does not involve adjustment of the pivot point of the rocker arm along a vertical axis.
The Burandt Patent (U.S. Pat. No. 4,484,546) discloses a variable valve operating mechanism for an internal combustion engine. Again, the mechanism adjusts an upper rocker arm along a distal end that is actuated via a servo mechanism.
The Hara et al. Patent (U.S. Pat. No. 4,438,736) discloses a variable valve timing arrangement with automatic valve clearance adjustment. However, the arrangement is not able to adjust the pivot point of the rocker arm along a vertical axis.
While the above-described devices fulfill their respective and particular objects and requirements, they do not describe a mechanically operated variable timing device that works to adjust the location of a pivot point for a rocket arm such that the pivot point may be adjusted along a vertical axis, and which is adjusted independent of RPM of the respective engine, and which is able to adjust the valve timing and lift to optimize timing and lift at different RPMs; wherein the mechanically operated variable timing device includes a cam that is able to rotate independent of engine RPM, and which engages a plunger positioned over the respective rocker arm; wherein the plunger is biased upwardly via a spring positioned between the ball fulcrum of the rocker arm and a bottom portion of the plunger; wherein a pivot shaft is threadably engaged to a threaded hole located on a top surface of the engine block; wherein the pivot shaft extends vertically through the rocker arm and ball fulcrum; wherein the pivot shaft extends into a bottom cavity located in the plunger in order to support the various componentry associated with the mechanically operated variable timing device. In this regard, the mechanically operable variable timing device for use with a rocker arm pivot point departs from the conventional concepts and designs of the prior art.